Improved oil-well drill



UNITED STATES PATENT OEEroE.

CHARLES FortsTEE, or PITTSBURG, PENNSYLVANIA.

IMPROVED OI L-WELL DRILL.

Specification forming part of Letters Patent No. 58,803, dated October 16, 1866.

To all whom it 'may concern p Be it known that I, CHARLES FoRsTEn, of Pittsburg,in the countyof Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Drills for Cutting Chambers in Oil, Salt, or Artesian Wells, and in holes for blasting or mining purposes; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings, making a part of this specification, in which- Figure l is a vertical section through the axis of the drill parallel with the plane of the cutters, the plunger being raised and the cutters drawn inside the drill. Fig. 2 is a View of the drill with the front half of the barrel removed, the drill standing in the same plane as before, plunger down and cutters out. Fig. 3 is an outside front view, drill being in same position as in Fig. 2. Fig. 4 is a view of the upper face of the abutment. Fig. 5 is a lower-face view of the plunger, and Fig. 6 illustrates the strokes of the cutters.

Like letters refer to like parts of each.

It is generally conceded that petroleum is to be found in greatest quantities in the veins or seams or pockets of certain rock formations; also, that water, either pure or impregnated with salt or other substances, is not infrequently found in similar veins, or flowing in channels beneath the surface of the earth. It

' also appears that oil, salt, and other wells often fail, or cease to be producing wells, either in consequence of a failure to strike such veins, seams, or pockets, or in consequence of the clogging of the interstices of the rock leading thereto by foreign matter. I propose by a chamberingdrill to reach such veins, seams, or pockets, or cut away or clean ou-t such foreign matter. Also, in mining and blasting operations it is often desirable to enlarge the lower end of the blasting-chamber, so as to afford additional room for the reception of powder or other explosive compound.

The nature of my invention, then, consists in the construction of a drill forcutting chambers in oil, salt,Artesian, or other wells of small bore, and holes drilled or bored in earth or rock for mining, blasting, or other purposes.

To enable others skilled 'in the'art to make and use my invention, I will proceed to describe its construction and operation.

In manufacturing, I employ any known ma-A terial adapted to the purpose. The devices which I employ are usually inclosed in or connected with a barrel, z. To the upper end of the barrel c, 1 attach a hollow head, a, on which the barrel z revolves, as hereinafter to be specified, the two being held together by the collar a', which is usually a ring, made of the proper size, and fastened inside the upper end of the barrel z by the setscrews a c".

Attached to the head a are springs s s s s, which are constructed of such size and outward curvature and weight as, by their pressure against the sides of the well, to prevent the head a from revolving with the barrel z. In the bottom face of the hollow head a, (represented in Fig. 5,) in notches left for the purpose, I hang pawls p p, one or more, in manner and for the purposes hereinafter to be described.

Through the head a and upper part of the barrel z works the rod or shaft b. To the lower end thereof is attached a plunger, b', and to its upper en d a swivel, c, to which I attach the rope or rod by which the drill is worked from above.

The swivel c, I usually connect with the shaft b by screw-head and socket c', and, when necessary, introduce between the swivel c and the shaft b a jam, sinking-bar, or other device ordinarily employed with drill-heads, to increase the weight of the drill, which it is sometimes necessary to do. The jam or sinking-bar, when thus used, I attach by the screw-head and socket above described.

On the shaft b, I usually place an adjustable collar or ring, c, commonly' made of some elastic material, as an indicator of the amount of play of the shaft b, and consequently of the diameter of the chamber cut at anyparticular stage of the work, as is hereinafter explained.

In notches in the lower face of the plunger b', I hang two or more cutters, d d, by pins or bolts d passing through the slots e in the heads of the cutters, the slots e usually being curved. The upper and lower faces of the cutters 01,1 commonly make nearly or quite perfect arcs of circles, the side faces of any desirable shape, though usually fla-t, and the edges f runnin g diagonally across the ends and making an angle each with the other, the one making oblique cuts on the side of the well in one direction, as indicated by red lines in Fig. 6, and the other following around as the cutters d and barrel z revolve, cutting obliquely across the cuts of the rst, as indicated by black lines in Fig. 6.

The length and curvature ofthe cutters d are governed chiefly by the diameter of the bore of the barrel z and the size of the chamber desired,but not entirely so, as I vary them somewhat when the character of the drilling to be done or other considerations so require.

The drill is operated, in the usual way, by raising it up a short distance and allowing it to fall by its own gravity. The drill is raised by lifting the shaft b, (to which the workingrope is attached,) which withdraws the cutters wholly or partially into the cavity of the barrel z, and on the downstroke, soon as the drilling apparatus strikes the bottom of the well, the cutters d d are forced outward, their cutting points or edges striking the side of the well or hole, in the manner above described,

with sufficient force to cut into the rock, and thus, by the aid of the regular rotary motion given to the apparatus, as hereinafter described, enlarging the cavity of the well all around, and accomplishing the functions of a chambering-drill.

Under the cutters d, and between the upper and lower sections of the barrel z, I place an abutment, g, fastened to the upper section by the bolt, screw, or rivet g, and to the lower section by the screws or bolts g. The upper face of the abutment g (represented in Fig. 4) I usually make with notches h h, said notches having a concave lower face, for the cutters d to play on.

The plunger" b is provided on its upper face with a ratchet, o, which, with the pawls p, secures the rotary motion of the plunger b and cutters d.

The abutment g is also made to revolve in the same direction by the pressure of the cutters d when revolving against the sides of the notches h, in which they play, which rotating motion is communicated by the abutment g to the barrel z, with which it is firmly connected, as above described.

The pawls p are each provided with a shoulder, a2, Fig. 2, which, striking against the rear face of the notch in which it is hung as the plunger b goes down, prevents the pawl p from falling so far as not to be carried up again when the plunger b rises. The pawl p has also a catch, fr', on its lower face, which plays into the teeth of the ratchet r as the latter rises with the rise of the plunger b', the teeth ofthe ratchet r being beveled in the direction of the swing of pawls p, so as to cause the rotary motion of the plunger b', shaft b, the cutters d, and with them the abutment g and barrel z, as above referredto.

The pawlsp, forward of the catch are usually constructed with a full face, w, which, struck by the ratchet-teeth as the plunger b rises, is thrown forward and upward, the better insuring'the regular and complete action of the pawls lo. The amount of rotary motion is. of course, at each upward stroke of the plunger b', regulated by and equal to the distance of the ratchet-teeth from each other, since the pawls p each take a new ratchettooth at every such stroke. Consequently cach succeeding stroke of the cutters d against the sides of the well will be the same distance in advance of the last preceding one.

In the lower end of -the barrel z, I insert screw-box, m, its upper end constructed usually in a conical or oval form, and resting against and playing inthe socket t' in the lower face of the abutment g. This screw-box m is supported from below by the collar u, the same being constructed, inserted, and fastened in the usual way.

In the screw-box m works the screw o, made of any desirable length, with an adjustable nut, 0. rlhe screw o has also a thread cut at its lower end, by which to attach it to pipe or tubing below, either for the purpose of firmly steadying the drill or'drawing up or putting down the tubing.

As the drilling progresses, and it becomes necessary to raise the drill for the purpose of enlarging the vertical depth of the chamber, I lower the screw 0 in the screw-box m, and tighten it in any desirable position by the adjustable nut o. The result of lowering the screw is the raising of the drill, whereby I bring the edges of the cutters d to any desirable points on the sides of the well, and so continuously, as successive sections of the chamber are cut, till one of the required size is obtained.

The collar or ring c" is made to fit closely around the shaft b, and thereby retain its position without sliding downward when the drill is being operated, and yet is susceptible of being pushed upward upon its shaft b by contact with the top of the head a. When the drill is about to be used for enlarging kthe bore of a well, the shaft b is raised until the cutters cl d are withdrawn into the cavity of the barrel z, and the collar is pushed down on the shaft b until it touches the head a. As the cutters expand or spread out more and more as they gradually enlarge the cavity or chamber of the well, the shaft b sinks lower at each stroke into the head a., and in so doing pushes up the ring or collar c on the shaft b, and thus, by its height on the shaft, the collar serves as a gage to indicate the diameter of the chamber made by the action of the drill.

What I claim as myinvention, and desire to secure by Letters Patent, is-

1. The combination, in a drillingtool, of curved cutters d, having slots e and oblique edges f, substantially in the manner and for the purposes above set forth.

2. The combination, in a drilling-tool,ot` the head a, the springs s, the plunger b', the ratchet r, the pawls p, for the purpose of producing a rotary motion and communicating the same to the cutters d, and barrel e, the Whole being` indicate lhe degree of spread of the critters constructed and arranged suhsmntialiy as sind Within the chamber of :n Weil. for the purposes above described. In testimony whereof I, the said CHARLES 3. The eombi11zx-tio1i,in a drilling-tool, of the FORSTER, have hereunto set my hand in presabutment g, screw-box m, screw o, and adjustenee of two witnesses. able jam-nut 0', used and operated substantiaily as and for the purposes above set forth.

4. The use of the ring or collar c, in oombiuation with the shaft b of a drilling-tool fmn4 l nished with expanding cutters, as ai gage io CHARLES FQRSTER.

Vitnesses: V

GEORGE H. GHRIs'rY, A. S. NICHOLSON. 

